Adjustable lamp bracket



April 12, 1949. I J. MAY 2,466,722

ADJUSTABLE LAMP BRACKET Filed 001. 27. 1947 INVENTOR.

' JOHN MAY BY ATTORNEY Patented Apr. 12, 1949 2,466,722 ADJUSTABLE LAMP BRACKET John May, Detroit, Mich. Application October 27, 1947, Serial No. 782,416

4 Claims.

This invention relates to adjustable brackets and particularly adjustable lamp brackets.

An object of the invention is to provide a lamp bracket, particularly suited to installations entailing rough usage, as in shops and in connection with machinery, such bracket affording a lamp thereon a high degree of three-dimensional adjustment, and being adapted to securely maintain any selected position of such adjustment.

Another object is to provide a lamp bracket having the aforementioned adjustability, and employing a less expensive and more readily as sembled construction than has heretofore been available.

Another object is to provide an elongated lamp bracket, universally jointed at various points between its ends and having novel clutch installations at said joints, resisting movement under any force below a predetermined magnitude.

These and various other objects are attained by the construction hereinafter described and illustrated in the accompanying drawing, wherein:

Fig. l is a perspective view of my improved bracket.

Fig. 2 is a fragmentary side elevational view, in partial section, of one of the universally pivotal joints of the bracket.

Fig. 3 is a cross sectional view of said joint taken on the line 3-3 of Fig. 2.

In these views, the reference character l designates a hollow base which may be rigidly secured to any suitable support by fastenings 2. Rigidly and centrally carried by such base is a standard 3 of inverted U shape. Universally pivoted on said standard is a pair of spaced parallel elongated link bars 4, the universal pivotal connection being as follows. A rivet 5 or the like pivotally mounts one end of a short metal tube 6 of square cross section upon and between. the posts of the standard 3, and a relatively transverse rivet 1 pivots corresponding ends of the bars 4 upon and at opposite sides of the other end of said tube. Coaxial with each rivet are two pairs of coacting clutch disks 8 and ii, the disks 8 being welded or otherwise fixed on the tube 6 and the disks 9 being similarly fixed on the inner faces of the standard 3 and bars A. The disks of each pair have their outer portions formed with radial corrugations it normally interfitting to resist angular play of the tube on the standard 3 and of the link bars on the tube. When a predetermined force is applied, however. the corrugations of any of said pairs of disks will spring apart sufficiently to afford their relative angular adjustment. To establish clearance at opposite sides of the corrugated portions of the disks adequate for momentary disengagement of the corrugations, the central portions of each pair of disks are dished to a spaced relation, as best appears in Fig. 2. As an additional provision for the desired play between the paired clutch disks, cupped washers ll of spring sheet metal are inserted between the heads of the rivets 5 and 1 and the standard 3 and bars 4, such washers affording a slight spreading apart of the bars 4 and of the posts of the standard, when the aforementioned predetermined stress is applied. Mounted on each rivet 5 and 1 within the tube 6 is a reinforcing sleeve I2 terminally engaging the tube walls carrying the rivets.

To the ends of the bars 4 remote from the tube 6, a similar pair of bars i3 is universally pivoted by a tube l4 duplicating the tube 6, the details of this joint further duplicating those already described. That is to say, the joint comprises relatively transverse rivets 5a and la, clutch disks 8a and 9a, cupped washers Ha. and reinforcing sleeves similar to l2. While it is obvious that the bracket might be extended for any desired length by further pairs of universally pivoted link bars, I have shown a lamp socket l5 universally pivotally mounted on the outer ends of the bars l3. This is accomplished by securing a U-shaped support It to the socket and connecting such support to the bars l3 by a square tube 11 duplicating those already described.

Threaded through the several tubes 6, f4, and H, and between the pairs of bars 4 and i3 is a pair of flexible electrical conductors i8 supplying current to the lamp socket, said conductors preferably passing through the base which has a lateral orifice IQ for that purpose.

The tubes and link bars described may be formed of standard material cut to suitable lengths. For this reason and by reason of the simple nature of the bracket and the repeated use of many of its parts, it may be manufactured at relatively low cost. The described clutch disks are an important time-saving feature, since they permit effecting and maintaining an angular adjustment at any of the various pivots without need for loosening and tightening screws.

While it is preferred to employ tubes much shorter than the link bars, since this facilitates threading conductors through such tubes, it is evident that the tubes may be given any desired length ratio to the link bars without departing from the principles of my construction.

What I claim is: extending through the tube, and a reinforcing 1. A lamp bracket comprising two pairs of sleeve mounted on the pivot member within the elongated bar links, the links of each pair havtube and substantially engaging opposite walls ing a spaced parallel relation, a'tube having its of the tube. respective end portions inserted between the links 5 4. In a lamp bracket, a tube of rectangular of the respective pairs, two relatively transverse cross section, a pair of spaced link bars straddling pivotal connections between the respective link an end of the tube, a pivotal connection between pairs and said tube, and an electrical conductor said tube and bars, and a pair of clutch disks beextended through said tube and between the tween the tube and each bar, one disk of each paired links. 10 pair being secured to the tube and the other two 2. A lamp bracket as set forth in claim 1, said disks being respectively secured to the respective tube being of substantially square cross section, bars, the paired disks having normally interfitand one pair of said link bars having flat faces ting corrugations radial to the axis of said piv. confronting two walls of said tube, and the other otal connection, and said disks being resilient to pair having flat faces confronting the other two 15 afford their relative rotation responsive to a walls of said tube. predetermined applied force.

3. A lamp bracket comprising a tube of rec- JOHN MAY. tangular cross section, a pair of spaced link bars straddling an end portion of said tube, a pivot N0 references Citedmember interconnecting said tube and bars and go 

